Rolling guide device and drive system using rolling guide device

ABSTRACT

A rolling guide device comprises: a track rail formed with a rolling member rolling surface extending along a longitudinal direction thereof; a movable rail formed with a loaded rolling member rolling surface extending along a longitudinal direction thereof so as to oppose to the rolling member rolling surface of the track rail; a track rail side rolling member circulation passage formed to the track rail so as to circulate the rolling members rolling between the track rail and the movable rail; a movable rail side rolling member circulation passage formed to the movable rail so as to circulate the rolling members rolling between the track rail and the movable rail; and a number of rolling members disposed and arranged in the track rail side rolling member circulation passage and the movable rail side rolling member circulation passage. A drive system comprises such rolling guide device and linear motors having a primary side mounted to either one of the track rail and the movable rail and a secondary side mounted to another one of the track rail and the movable rail.

[0001] The present application claims priority under 35 U.S.C §119 toJapanese Patent Application No.2000-073932 filed Mar. 13, 2000 entitled“ROLLING GUIDE DEVICE ”, No.2000-367605 filed Dec. 1, 2000 entitled“ROLLING GUIDE DEVICE AND DRIVE SYSTEM USING ROLLING GUIDE DEVICE”, andNo.2001-037486 filed Feb. 14, 2001 entitled “ROLLING GUIDE DEVICE ANDDRIVE SYSTEM USING ROLLING GUIDE DEVICE”. The contents of thatapplication are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a rolling guide device in whicha movable rail is made slidable with respect to a track rail and alsorelates to a drive system using such rolling guide device.

[0003] As a rolling guide device in which a movable rail is madeslidable with respect to a track rail, there has been known a slide railsuch as shown in FIG. 25 (see Japanese Utility Model Publication No. SHO62-8765). Such slide rail comprises a track rail member 1 having anopened recess 1 a (i.e. having substantially

-shaped (box-shaped) cross section) formed by both inner side surfaces 1b, 1 b and a bottom surface 1 c and a movable rail member 2 which issupported between both the inner side surfaces 1 b, 1 b of the trackrail member 1 to be movable in the longitudinal direction thereof. Themovable rail member 2 also has an opened recess 2 a (i.e. havingsubstantially

-shaped (box-shaped) cross section).

[0004] The track rail member 1 and the movable rail member 2 havesubstantially the same longitudinal length. The inner side surfaces 1 bof the track rail member 1 are formed with ball rolling grooves,respectively, along which balls roll in the longitudinal directionthereof, and outer side surfaces 2 b of the movable rail member 2 arealso formed with loaded ball rolling grooves, respectively, so as toextend in the longitudinal direction thereof and oppose to the ballrolling grooves formed to the track rail member 1.

[0005] A number of balls 3 are arranged and housed between these ballrolling grooves and loaded ball rolling grooves, and these balls 3 areheld by a cage 4 to be rotatable and slidable. When the movable railmember 2 is slid with respect to the track rail member 1 in thelongitudinal direction thereof, these balls 3 roll and, hence, the sliderail becomes smoothly expandable or contractive.

[0006] Further, though not shown, there is also known a cam-followertype drawer device of a structure that movable and track rails are bothprovided with wheels so that the movable rail is drawn with respect tothe track rail, as a rolling guide device in which a movable rail isslidable with respect to a track rail.

[0007] However, in the conventional slide rail such as mentioned above,a number of balls 3 disposed and arranged between the track rail member1 and the movable rail member 2 do not completely perform the rollingmotion and will roll with a slight sliding motion. In the conventionalslide rail, since the balls 3 do not circulate and only reciprocallymove along the loaded rolling passage between the ball rolling groovesand the loaded ball rolling grooves, if the balls 3 are slid, the cage 4supporting (bearing) the balls 3 would be displaced from the initialposition. As a result, in spite of the fact that an effective stroke ofthe movable rail member 2 is not achieved, the cage 4 collides with astopper 5 of the track rail member 1 and, hence, such effective strokecould not be obtained. In this case, when it is required to slide themovable rail member 2 with the cage 4 colliding with the stopper 5, themovable rail member 2 will be slid with the balls 3 being slipped, andaccordingly, a large force is required to move the movable rail member2.

[0008] Furthermore, in the conventional structure of the slide rail, inorder to obtain a large stroke of the movable rail member 2, it isnecessary for the movable rail member 2 to be once come off from aportion at which the balls 3 exist and then to be engaged with thatportion at which the balls 3 exist. That is, in the case where themovable rail member 2 is come off from the portion at which the balls 3exist, for example, the movable rail member 2 which has been loaded withten (10) balls 3 is loaded with, for example, six (6) balls 3, andhence, ability for bearing moment load, radial load and thrust load isdeteriorated, thus being inconvenient.

[0009] Moreover, with the cam-follower type drawer device, since thewheels generally have backlash or looseness, the movable rail member 2is not smoothly slid, and furthermore, since the wheel has a cylindricalstructure, a direction along which a load is received is determined, andhence, the thrust load cannot be received.

SUMMARY OF THE INVENTION

[0010] An object of the present invention is to substantially eliminatedefects or drawbacks encountered in the prior art mentioned above and toprovide a rolling guide device capable of taking a largeexpansion/contraction stroke and sufficiently bearing moment load,radial load and thrust load at any expanded (contracted) attitude andalso provide a drive system incorporated with such rolling guide device.

[0011] This and other objects can be achieved according to the presentinvention by providing, in one aspect, a rolling guide devicecomprising:

[0012] a track rail formed with a rolling member rolling surfaceextending along a longitudinal direction thereof;

[0013] a movable rail formed with a loaded rolling member rollingsurface extending along a longitudinal direction thereof so as to opposeto the rolling member rolling surface of the track rail;

[0014] a track rail side rolling member circulation passage formed tothe track rail so as to circulate the rolling members rolling betweenthe track rail and the movable rail;

[0015] a movable rail side rolling member circulation passage formed tothe movable rail so as to circulate the rolling members rolling betweenthe track rail and the movable rail; and

[0016] a number of rolling members disposed and arranged in the trackrail side rolling member circulation passage and the movable rail siderolling member circulation passage.

[0017] According to the invention of this aspect, when the movable railis slid with respect to the track rail, the rolling members arrangedbetween the track rail and the movable rail endlessly circulate in thetrack rail side rolling member circulation passage and the movable railside rolling member circulation passage while rolling therealong. Asmentioned, since the rolling members circulate in the endless manner,even if the rolling member slides during the rolling motion, there is nocausing of a case that a cage is shifted from the initial position as inthe conventional structure, and hence, a large expansion (contraction)stroke is obtainable. Furthermore, in an optional expanded (contracted)attitude, there remains a considerable distance between the track railside rolling member circulation passage and the movable rail siderolling member circulation passage, so that a rolling guide device,which can bear even the moment load, can be realized.

[0018] Further, when the movable rail is slid and its stroke is madelarge, the considerable distance corresponding to this stroke is madeshort and capability of bearing the moment load is reduced. However,according to the present invention, the movable rail is not come offfrom the balls, so that the capability of bearing the moment load is notextremely reduced. Moreover, since the movable rail is not come off fromthe balls and the number of the rolling members supported at an optionalexpansion (contraction) attitude is not changed, different from theconventional slide rail, there can be provided a rolling guide devicebearing the constant radial load and thrust load.

[0019] In the above aspect, the following preferred embodiments orexamples may be provided with advantageous functions and effectsthereof.

[0020] The track rail side rolling member circulation passage is formedto one longitudinal end side of the track rail and the movable rail siderolling member circulation passage is formed to one longitudinal endside, opposing to that one end side of the track rail, of the movablerail.

[0021] Accordingly, the distance between the track rail side rollingmember circulation passage and the movable rail side rolling membercirculation passage can be made large, so that a rolling guide devicebearing the large moment load can be provided.

[0022] Furthermore, the track rail has an opened recess having a

-shaped section and has inside surfaces to which the rolling memberrolling surfaces are formed, the movable rail is fitted into the recessof the track rail, and the movable rail has outside surfaces to whichthe loaded rolling member rolling surfaces are formed so as to oppose tothe rolling member rolling surfaces formed to the track rail insidesurfaces.

[0023] Thus, various kinds of loads including radial load, thrust loadand moment load can be supported in a balanced condition.

[0024] The track rail side rolling member circulation passage isprovided with a rolling member return passage substantially parallel tothe rolling member rolling surface and a rolling direction changingpassage communicating the rolling member rolling surface and the rollingmember return passage, the movable rail side rolling member circulationpassage is provided with a rolling member return passage substantiallyparallel to the loaded rolling member rolling surface and a rollingdirection changing passage communicating the rolling member rollingsurface and the rolling member return passage, the rolling directionchanging passages of the track rail side rolling member circulationpassage and the movable rail side rolling member circulation passage areformed to a deflector which is formed independently from a track railbody and a movable rail body, and the deflector is fitted to holesformed to the track rail body and movable rail body from the sideportions thereof.

[0025] According to this embodiment, the rolling direction changingpassages can be easily formed to fine long track rail and movable rail.

[0026] The return passages are drilled to the track rail body and themovable rail body from the longitudinal end portions thereof.

[0027] According to this embodiment, the return passages can be easilyformed to fine long track rail and movable rail.

[0028] The deflector is composed of a plurality of sections splittablealong the rolling direction changing passages.

[0029] Accordingly, the rolling direction changing passages havingcomplicated structure may be easily formed to the deflector.

[0030] The deflector is made of a synthetic resin.

[0031] Accordingly, the rolling direction changing passages havingcomplicated structure may be easily formed to the deflector, andmoreover, noise which may be generated when the rolling members roll inthe rolling direction changing passages will be suppressed.

[0032] The above mentioned object of the present invention can be alsoachieved by providing, in another aspect, a drive system comprising:

[0033] a track rail formed with a rolling member rolling surfaceextending along a longitudinal direction thereof;

[0034] a movable rail formed with a loaded rolling member rollingsurface extending along a longitudinal direction thereof so as to opposeto the rolling member rolling surface of the track rail;

[0035] a track rail side rolling member circulation passage formed tothe track rail so as to circulate the rolling members rolling betweenthe track rail and the movable rail;

[0036] a movable rail side rolling member circulation passage formed tothe movable rail so as to circulate the rolling members rolling betweenthe track rail and the movable rail;

[0037] a number of rolling members disposed and arranged in the trackrail side rolling member circulation passage and the movable rail siderolling member circulation passage; and

[0038] a linear motor means having a primary side mounted to either oneof the track rail and the movable rail and a secondary side mounted toanother one of the track rail and the movable rail.

[0039] According to the present invention of this aspect, the expansion(contraction) stroke can be made large and the moment load, the radialload and the thrust load can be sufficiently supported at an optionalattitude of the system. Furthermore, since the linear motors areincorporated between the track rail and the movable rail, the use of theball screw or like can be eliminated, thus moving the movable rail athigh speed with less noise. Moreover, since it is not necessary toprovide a space for a rotary motor, the drive system can be made thinand compact.

[0040] According to preferred embodiments or examples of this aspect,the following advantageous functions and effects may be attained.

[0041] The track rail side rolling member circulation passage is formedto one longitudinal end side of the track rail and the movable rail siderolling member circulation passage is formed to one longitudinal endside, opposing to that one end side of the track rail, of the movablerail, and the linear motor means comprises first and second linearmotors, the first linear motor having a primary side mounted to aportion near the track rail side rolling member circulation passage ofthe track rail, the second linear motor having a secondary side mountedto the track rail along the longitudinal direction thereof so as to becontinuous to the primary side of the first linear motor, and the secondlinear motor having a primary side mounted to a portion near the movablerail side rolling member circulation passage of the movable rail, thefirst linear motor having a secondary side mounted to the movable railalong the longitudinal direction thereof so as to be continuous to theprimary side of the second linear motor.

[0042] According to this embodiment, since two sets of linear motors areincorporated in the drive system, the thrust force can be made two times(twice), and the excitation is averaged to thereby make smooth themovement of the movable rail. Furthermore, the first linear motor has aprimary side mounted to a portion near the track rail side rollingmember circulation passage of the track rail and the second linear motorhas a primary side mounted to a portion near the movable rail siderolling member circulation passage of the movable rail, so that thethrust force can be generated at substantially the same positions of themovable side rolling member circulation passage and the track rail siderolling member circulation passage, regardless of the stroke of themovable rail. Therefore, even if pitching or yawing moment is applied tothe movable rail, the thrust force can be stably applied to the movablerail.

[0043] The first and second linear motors may be composed of linearinduction motors or linear pulse motors such that the secondary sidesthereof are opposed to each other.

[0044] For example, in a case where linear D.C. motors are used, twosets of linear motors are disposed in back-to-back arrangement and adistance between the secondary side magnets is short, an alternatingmagnetic field may be generated between the magnets. However, accordingto this embodiment of the present invention, since the linear inductionmotors or linear pulse motors are used without using the magnets, thereis no fear of causing any alternating magnetic filed. However, a linearD.C. motor may be utilized as far as a relatively large distance betweenthe secondary sides of the linear D.C. motors can be taken so as not toinfluence from each other.

[0045] The nature and further characteristic features of the presentinvention may be made clear from the following descriptions made withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In the accompanying drawings:

[0047]FIG. 1 is a perspective view of a rolling guide device accordingto one embodiment of the present invention;

[0048]FIG. 2 is a transverse sectional view of the rolling guide deviceof FIG. 1, partially cut away, in the longitudinal direction thereof;

[0049]FIG. 3 is a sectional view in a direction normal to the axis ofthe rolling guide device;

[0050]FIG. 4 is a perspective view showing a ball screw to beincorporated in the rolling guide device of FIG. 1;

[0051]FIG. 5 is a perspective view showing one example of a deflector tobe assembled with the rolling guide device;

[0052]FIG. 6 is a perspective view showing another example of thedeflector;

[0053]FIG. 7 is a perspective view of a drive system using the rollingguide device of FIG. 1;

[0054]FIG. 8 is an illustration showing a state that a load is appliedto a front end portion of the rolling guide device of FIG. 1;

[0055]FIG. 9 is an illustration of a further embodiment of the rollingguide device and includes FIG. 9A showing a two-stage type rolling guidedevice and FIG. 9B showing a three-stage type rolling guide device;

[0056]FIG. 10 is a perspective view of a drive system, according toanother embodiment of the present invention, incorporated with a linermotor;

[0057]FIG. 11 is a transverse sectional view of the drive system of FIG.10, partially cut away, in the longitudinal direction thereof;

[0058]FIG. 12 is a sectional view taken along the line XII-XII in FIG.10;

[0059]FIG. 13 is a sectional view taken along the line XIII-XIII in FIG.10;

[0060]FIG. 14 is an illustration showing an example in which two set oflinear motors are disposed in back-to-back arrangement;

[0061]FIG. 15 is a perspective view showing a linear induction motor;

[0062]FIG. 16 is a vertical sectional view of a liner pulse motor in alongitudinal direction thereof;

[0063]FIGS. 17A to 17D show operation principle of the liner pulsemotor;

[0064]FIG. 18 is a perspective view of a linear D.C. motor;

[0065]FIG. 19 is a perspective view showing a drive system according toa further embodiment of the present invention;

[0066]FIG. 20 is a sectional view of a rolling guide device formed withlateral two rows of rolling member (ball) rolling grooves;

[0067]FIG. 21 is a view showing a contacting state of a ball to a ballrolling groove and a loaded ball rolling groove (circular-arc groove);

[0068]FIG. 22 is a view showing a contacting state of a ball to a ballrolling groove and a loaded ball rolling groove (Gothic-arch groove);

[0069]FIG. 23 is a sectional view of one example of a rolling guidedevice using rollers as rolling members;

[0070]FIG. 24 is a sectional view of another example of a rolling guidedevice using rollers as rolling members; and

[0071]FIG. 25 is a perspective view showing a slide rail having aconventional structure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0072] FIGS. 1 to 3 represent a first embodiment of a rolling guidedevice according to the present invention.

[0073] With reference to FIGS. 1 to 3, a rolling guide device comprisesan outer rail 7 as a track rail, an inner rail 8, as a movable rail,supported by the outer rail 7 to be slidable in the longitudinaldirection thereof and a ball screw 9 driving the inner rail 8. When ascrew shaft 10 of the ball screw 9 is rotated, the inner rail 8 is slidwith respect to the outer rail 7. Such rolling guide device will beutilized for a welding servo-gan, fork-lift or like usable in astockroom, for example. In a case where the rolling guide device isutilized for the welding servo-gan, a welding rod is attached to theinner rail 8 and, then, the inner rail 8 is slid so as to press thewelding rod against an object to be welded. On the other hand, in a casewhere the rolling guide device is utilized for the fork-lift, an innerrail 8 having a front fork member is slid and the fork-lift is thenmoved while supporting a cargo by the projected fork member. It is ofcourse to be noted that the illustrated rolling guide device is notlimited in its use to the welding servo-gan and the fork-lift and can beapplied for various usages as far as expansion/contraction stroke isrequired and a load is supported.

[0074] The outer rail 7 has a recess 7 a having an upper opening, in anillustrated state, so as to provide substantially a

-shaped (box-shaped) section having an upper opening. That is, therecess 7 a is defined by a bottom portion and a lateral pair of ridges 7b, 7 b extending in parallel to each other at both longitudinal sideportions of the bottom portion. Each of the ridges 7 b has an insidesurface 7 c to which one row of ball rolling groove 11 is formed as arolling member rolling surface extending in the longitudinal directionthereof. An outer rail side ball circulation passage 14 for circulatingballs 13, as rolling members, rolling between the inner rail 8 and theouter rail 7 is formed to one longitudinal side end portion of the outerrail 7.

[0075] The inner rail 8 is fitted to the recess 7 a of the outer rail 7and supported thereby through balls 12, 13 so as to be clamped betweenthe ridges 7 b, 7 b of the outer rail 7. The inner rail 8 has a recess 8a having a lower opening, in an installed state, so as to providesubstantially a

-shape section having a lower opening, thus easily forming a space intowhich the screw shaft 10 is moved.

[0076] In the fitted state of the inner and outer rails 8 and 7, theinside surfaces 7 c, 7 c of the outer rail 7 face the outside surfaces 8c, 8 c of the inner rail 8, respectively, so that the ball rollinggrooves 11 formed to the inside surfaces 7 c, 7 c of the outer rail 7oppose to the loaded ball rolling grooves 15 formed to the outsidesurfaces 8 c, 8 c of the inner rail 8. Inner rail side ball circulationpassages 16 are formed to one longitudinal end side of the inner rail 8opposing to the outer rail side ball circulation passages 14 so as tocirculate the balls 12 rolling between the outer and inner rails 7 and8. That is, in the structure in which the inner rail 8 projects from(extends over) the outer rail 7, the outer rail side ball circulationpassages 14 on the exit side end of the outer rail 7 and the inner railside ball circulation passages 16 are formed to the rear side end of theinner rail 8. This will be explained through a manufacturing processes.The outer rail side ball circulation passages 14 are formed to one endside of the outer rail 7 and the inner rail side ball circulationpassages 16 are formed to one end side of the inner rail 8, andthereafter, the inner and outer rails 8 and 7 are assembled (fitted)from the direction in which both the circulation passages 14 and 16 donot interfere.

[0077] As shown in FIG. 2, each of the outer rail side ball circulationpassages 14 is composed of a portion of the ball rolling groove 11, aball return passage A as a rolling member return passage substantiallyparallel to the ball rolling groove 11 and a pair of rolling memberrolling direction changing passages B communicating with the ballrolling groove 11 and the ball return passage A. On the other hand, eachof the inner rail side ball circulation passage 16 is also composed of aportion of the loaded ball rolling groove 15, a ball return passage A asa rolling member return passage substantially parallel to the ballrolling groove 15 and a pair of rolling member rolling directionchanging passages B communicating with the loaded ball rolling groove 15and the ball return passage A. The ball return passage A is formedthrough a drilling working effected along the longitudinal directionfrom the end portions of an outer rail body 7 d and an inner rail body 8d. The rolling direction changing passages B formed to the outer andinner ball circulation passages 14 and 16 are formed to deflectors 19formed independently from the inner and outer rail bodies 8 d and 7 d.The details of such deflector 19 will be described hereinlater.

[0078] The ball screw 9 is engaged with the inner rail 8 so that theball screw 9 is arranged in the recess 8 a of the inner rail 8.

[0079] With reference to FIG. 4 showing the ball screw 9, the ball screw9 comprises the screw shaft 10, a nut member 22 assembled to the screwshaft 10 to be relatively movable and a number of balls 23 disposed inthe ball circulation passage. The screw shaft 10 has an outer peripheralsurface on which a spiral rolling member rolling groove 10 a is formed,the nut member 22 has an inner peripheral surface to which is formed aball circulation passage including a spiral loaded rolling memberrolling groove 22 a opposing to the ball rolling groove, and the numberof balls 23 are arranged in the ball circulation passage so as tocirculate therein in association with the relative movement of the nutmember 22 with respect to the screw shaft 10. The nut member 22 has aflanged portion 24 formed at its one end side and is secured to theinner rail 8 by means of screws or like. The nut member 22 is alsoprovided with a deflector 25 (direction changing passage forming member)for taking out the ball 23 rolling along the ball rolling groove 10 aformed to the screw shaft 10 at one portion thereof and returning theball 23 to the other portion (one-lead on this side from the ball takenout portion) of the ball rolling groove 10 a over an outer largediameter portion of the screw shaft 10. The screw shaft 10 isoperatively coupled with an output (drive) shaft of a motor, mentionedhereinlater.

[0080] When the screw shaft 10 is rotated, the ball 23 rolling in thecircumferential direction of the screw shaft under load is scooped up bythe deflector 25 and the scooped ball 23 is then returned to theposition, one-lead on this side of the ball rolling groove 10 a. Whenthe screw shaft 10 is rotated in the reverse direction, the balls 23 arecirculated along the route reverse to that mentioned above. Further, inthe described embodiment, although the balls 23 are scooped up by usingthe direction changing passage forming member (deflector) 25 andreturned to the position, one-lead on this side of the ball rollinggroove 10 a, a return pipe may be substituted for such deflector 25.That is, according to the structure using the return pipe, the ball 23rolling along the ball rolling groove 10 a of the screw shaft 10 isscooped up by one end of the return pipe and is then returned throughthe other one end thereof. Furthermore, so-called a side-cover (lid)type ball screw may be adapted, in which the nut member 22 is composedof a nut body formed with a loaded rolling groove and side lids appliedto both ends of this nut body, a ball return passage is formed to thenut body, and both the side lids are formed with communication passagescommunicated with the loaded rolling groove and the return passage,respectively. An arrangement utilizing rollers in place of balls may bealso applicable to the present invention.

[0081]FIG. 5 shows the details of the deflector 19, which is utilizedcommonly for the inner rail side ball circulation passage 16 and theouter rail side ball circulation passage 14. With reference to thedeflector 19 of FIG. 5, the deflector 19 is formed with rollingdirection changing passage 26 in a semi-circular shape, and thedeflector is composed of two bodies 19 a and 19 b divided along therolling direction changing passage 26 for the sake of easy formation ofthis passage 26. That is, these two body sections 19 a and 19 b aredivided vertically, as viewed, through a plane including a central lineof the rolling direction changing passage 26. Both the body sections 19a and 19 b are positioned through the engagement of dowels 27 and holes28 formed to the body sections 19 a and 19 b. The deflector 19 isfurther formed with a stepped abutment portion 29 for the purpose ofpositioning it to the inner rail side ball circulation passage 16 andthe outer rail side ball circulation passage 14. The deflector 19 of thestructure mentioned above will be formed from synthetic resin, forexample, through an injection formation process.

[0082]FIG. 6 shows another example of the deflector 30. This deflector30 is also composed of two divided body sections 30 a and 30 b separatedalong the rolling direction changing passage 26 for the easy formationthereof as mentioned before. In this example, however, the rollingdirection changing passage 26 is divided into two sections as innerperipheral side section and outer peripheral side section. Thisdeflector 30 is also formed with a stepped abutment portion 31.

[0083] With reference to FIGS. 2 and 3, the outer rail body 7 d isdrilled from the side thereof to form holes 33 by means of end mill, forexample, and the deflectors 19 are fitted to these holes 33. The fitteddeflectors 19 is secured to the outer rail body 7 d by fastening means32 such as binder members. The holes 33 are formed so as to penetratethe ball return passages A and extend ball rolling grooves 11 or ballrolling grooves 15 and formed inside with stepped portions 33 a abuttingagainst the abutment portions 29 of the deflectors 19. When fitting thedeflector 19, the outer periphery of the deflector 19 is fitted to thehole 33 and the abutment portion 29 of the deflector 19 abuts againstthe stepped portion 33 a of the hole 33, thus positioning the deflector19 with respect to the outer rail body 7 d or inner rail body 8 d.

[0084] Through such positioning of the deflector 19, the balls 12 and 13can be surely scooped from the ball rolling groove 11 or loaded ballrolling groove 15 and then returned to the ball return passage A.

[0085] On the other hand, other holes 33 are formed to the inner railbody 8 d from the side thereof by means of end mill, for example, andthe deflectors 19 are fitted to these holes 33. Furthermore, in thedescribed embodiment, although the holes 33 are formed to the outer railbody 7 d from the outside thereof and formed to the inner rail body 8 dfrom the inside thereof, the holes 33 may be formed to the outer railbody 7 d from the inside thereof and formed to the inner rail body 8 dfrom the outside thereof.

[0086]FIG. 7 shows one preferred example of a drive system according tothe present invention, which uses the rolling guide device mentionedabove and is assembled with a rotation motor.

[0087] The screw shaft 10 is screwed with the nut member 22 and has oneend rotatably supported by a bearing 35 disposed at one end portion ofthe outer rail 7 and coupled to a motor, not shown, through a jointmember 36. According to this structure, when the motor is driven, thescrew shaft 10 is rotated and the rotational motion thereof istransferred to the inner rail 8 through the ball screw to therebylinearly move the inner rail 8 along the outer rail 7. According to thislinear motion of the inner rail 8 along the outer rail 7, the rollingguide device is expanded or contracted, and the balls 12 and 13circulate in an endless manner in the inner rail side ball circulationpassage 16 and the outer rail side ball circulation passage 14 whilerolling therealong. Since the balls 12 and 13 endlessly circulate, evenif the balls 12 and 13 be slid during the rolling motion, there is nofear of being shifted from the original position as in a conventionalslide rail, and a rolling guide device having a large expansion strokecan be realized, in which the inner rail 8 can be smoothly moved.

[0088]FIG. 8 is an illustration showing a state that a load P is appliedto the front end of the inner rail 8 of the rolling guide device. In anoptional expanded or contracted state, since a considerable distance 1exists between the outer rail side ball circulation passage 14 and theinner rail side ball circulation passage 16, there can be provided arolling guide device bearing the moment load. For example, when the loadP is applied to the front end portion of the inner rail 8, a reactionforce Ro acts on the outer rail side ball circulation passage 14 and areaction force Ri acts on the inner rail side ball circulation passage16, thus bearing the moment load of (Ri×1). When the inner rail 8 slidesand the stroke of the rolling guide device is made large, theabove-mentioned distance 1 is gradually reduced and an ability forloading this moment load is also reduced. However, even if the innerrail 8 is slid, the inner rail 8 never come off as in the conventionalslide rail from the balls, so that the moment load bearing abilitycannot be largely reduced. Furthermore, the movable rail is not come offfrom the ball as in the conventional slide rail and the number of ballsborn in the optional expanded or contracted attitude does not change, sothat a rolling guide device capable of bearing constant radial load andthrust load can be realized.

[0089] Furthermore, as mentioned above, the outer rail 7 has a recess 7a having an upper opened portion has a box-shaped section and the ballrolling grooves 11 are formed to the inside surfaces 7 c, respectively.The inner rail 8 is fitted into the recess 7 a of the outer rail 7 andthe loaded ball rolling grooves 15 are formed to the outside surfaces 8c of the inner rail 8 so as to oppose to the inside surfaces 7 c of theouter rail 7. Accordingly, there is provided the rolling guide devicecapable of bearing the radial load, the thrust load and the moment loadin a balanced condition.

[0090]FIG. 9 includes perspective views of the rolling guide deviceaccording to another embodiment of the present invention. Referring toFIG. 9A, the device is provided with inner and outer rails 8 and 7,constituting a single-stroke structure in which only the inner rail 8 isslid. Further, as shown in FIG. 9B, the rolling guide device may becomposed of three rail sections comprising the outer rail 7, a firstinner rail 41 fitted to the outer rail 7 and a second inner rail 42fitted to the first inner rail 41. In this structure, the first innerrail 41 is slid with respect to the outer rail 8 and the second innerrail 42 is slid with respect to the first inner rail 41. That is, thefirst inner rail 41 acts like the inner rail 8 of the aforementionedembodiment with respect to the outer rail 7 and also acts like the outerrail 7 of the aforementioned embodiment with respect to the second innerrail 42. The second inner rail 42 has a structure identical to that ofthe inner rail 8. According to this rolling guide device of theembodiment of FIG. 9B, since the first inner rail 41 is slid with doublestrokes, the expansion stroke can be made further long. As mentionedabove, when the rolling guide device is composed of a plurality ofmembers (rail members), the expansion stroke composed of a plurality ofexpansion stages can be realized, thus providing a rolling guide devicehaving a large stroke.

[0091] In the embodiment described above, although the inner rail sideball circulation passage 16 and the outer rail side ball circulationpassage 14 are formed to the inner rail 8 and the outer rail 7,respectively, these passages may be formed as block membersindependently from the inner and outer rails 8 and 7. Furthermore,although the inner rail 8 and the outer rail 7 are formed as linear(straight) rail members, a curved rail member may be utilized therefor.The balls may be also substituted with other rolling members such asrollers. Retainers each having a belt shape having flexibility may bearranged for supporting the balls 12 and 13 to be rotatable, and spacersmay be also arranged between the balls 12 and 13 for supporting them tobe rotatable and slidable.

[0092]FIGS. 10 and 11 represent a drive system, using a linear motor asdrive source, according to one embodiment of the present invention.

[0093] This drive system comprises an outer rail 7 as a track rail, aninner rail 8 as a movable rail supported by the outer rail 8 to belinearly slidable along the longitudinal direction thereof and first andsecond linear motors 51 and 52 disposed between the inner and outerrails 8 and 7 to be back-to-back arrangement. The outer rail 7 isprovided with a primary side movable piece (called merely movable piecei hereinlater) of the first linear motor 51 and a secondary sidestationary piece (called merely stationary piece O′ hereinlater) of thesecond linear motor 52. On the other hand, the inner rail 8 is providedwith a secondary side movable piece (called merely movable piece i′hereinlater) of the second linear motor 52 and a primary side stationarypiece (called merely stationary piece O hereinlater) of the first linearmotor 51. According to this structure, when energized, suction(attracting) forces are induced between the movable piece i and thestationary piece O and between the movable piece i′ and the stationarypiece O′.

[0094] As like as the rolling guide device mentioned above, the outerrail 7 is formed with a recess 7 a having a box-shaped section with anupper opening and also formed with a lateral pair of ridges 7 b, 7 bextending on both the sides of the recess 7 a in parallel to each otheralong the longitudinal direction of the outer rail 7. Each of the ridges7 b, 7 b has an inside surfaces 7 c, to which a single row of ballrolling groove 11 as a rolling member rolling surface is formed so as toextend along the longitudinal direction thereof as shown in FIG. 11. Anouter rail side ball circulation passage 14 for circulating the balls 13rolling between the inner and outer rails 8 and 7 is formed to one(front) end side portion of the outer rail 7.

[0095] The inner rail 8 is fitted to the recess 7 a of the outer rail 7and supported thereby so as to be clamped between the ridges 7 b of theouter rail 7 through the balls 12 and 13. The inner rail 8 is alsoformed with a recess 8 a having an opening opened downward so as toprovide a box-shaped section. The inner rail 7 has outside surfaces 8 cto which loaded ball rolling grooves 15 are formed as loaded rollingmember rolling surfaces which face the ball rolling grooves 11 of theouter rail 7. An inner rail side ball circulation passage 16 forcirculating the balls 12 rolling between the inner and outer rails 8 and7 is formed to one (rear) end side portion of the outer rail 7 in thelongitudinal direction thereof.

[0096] As shown in FIG. 11, the outer rail side ball circulation passage14 is composed of a portion of the ball rolling groove 11, a ball returnpassage A as a rolling member return passage extending substantially inparallel to the ball rolling groove 11 and a pair of rolling directionchanging passages B communicated with the ball rolling groove 11 and theball return passage A. On the other hand, the inner rail side ballcirculation passage 16 is also composed of a portion of the loaded ballrolling groove 15, a ball return passage A as a rolling member returnpassage extending substantially in parallel to the loaded ball rollinggroove 15 and a pair of rolling direction changing passages Bcommunicated with the loaded ball rolling groove 15 and the ball returnpassage A. The ball return passages A are formed through drillingworking effected from the end portions of the outer rail body 7 d andthe inner rail body 8 d in their longitudinal directions. The rollingdirection changing passages B of the outer rail side ball circulationpassage 14 and the inner rail side ball circulation passage 16 areformed to a deflector 19 which is mounted to the inner rail body 8 d andthe outer rail body 7 d as independent member.

[0097] Holes 33 are formed to the outer rail body 7 d by means of endmill, for example, from the longitudinal sides thereof, and thedeflector 19 is fitted to these holes 33 and then fastened to the outerrail body 7 d. Holes 33 are also formed to the inner rail body 8 d bymeans of end mill, for example, from the longitudinal sides thereof, andthe deflector 19 is fitted to these holes 33 and then fastened to theinner rail body 8 d. Since these deflectors have substantially the samestructures as that mentioned herein before with reference to the rollingguide device, the details thereof are omitted herein by adding the samereference numeral of 19.

[0098] Two linear motors 51 and 52 are interposed between the inner rail8 and the outer rail 7, and the linear motors 51 and 52 in thisembodiment are linear induction motors and composed of the movablepieces i and i′ and the stationary pieces O and O′, the induction motorsbeing driven and operated by passing polyphase alternating current toprimary windings of the movable pieces i and i′.

[0099] With reference to FIG. 10, the movable piece i of the firstlinear motor 51 is mounted to a portion near one end (front end) in thelongitudinal direction of the upper surface of the outer rail 7, and thestationary piece O′ of the second linear motor 52 is also mounted to theupper surface of the outer rail 7 so as to be continuous to the movablepiece i of the first linear motor 51 in the longitudinal direction ofthe outer rail 7. On the other hand, the movable piece i′ of the secondlinear motor 52 is mounted to a portion near one end (rear end) in thelongitudinal direction of the lower surface of the inner rail 8, and thestationary piece O of the first linear motor 51 is also mounted to thelower surface of the inner rail 8 so as to be continuous to the movablepiece i′ of the second linear motor 52 in the longitudinal direction ofthe inner rail 8. In such arrangement, the movable piece i of the firstlinear motor 51 and the outer rail side ball circulation passage 14 havesubstantially the same positions in the longitudinal direction of theouter rail 7, and on the other hand, the movable piece i′ of the secondlinear motor 52 and the inner rail side ball circulation passage 16 havesubstantially the same positions in the longitudinal direction of theinner rail 8. Further, it is to be noted that the terms “upper”, “lower”and the like are used herein in the illustrated state in the figures orusable state of the device or system.

[0100] As shown in FIG. 12, the movable piece i of the first linearmotor 51 is opposed to the stationary piece O of the first linear motor51, and as shown in FIG. 13, the movable piece i′ of the second linearmotor 52 is opposed to the stationary piece O′ of the second linearmotor 52 so that the first and second linear motors 51 and 52 aredisposed in the back-to-back arrangement as shown in FIG. 14.

[0101]FIG. 15 shows a linear induction motor 53 constituting one exampleof the first and second linear motors 51 and 52. The linear inductionmotor 53 is provided with the movable piece i and the stationary piece Owhich is composed of a non-magnetic conductor plate 54 and a magneticconductor plate 55 by laminating them vertically as viewed. This linearinduction motor 53 is driven in a manner basically identical to that ofa cage (rotary type) induction motor having an operational functionexplained by the Lenz's law and the Fleming's left-hand rule.

[0102] When the polyphase alternating current passes the polyphaseprimary winding 56, a traveling (progressive) magnetic field movingtimely and spacially is generated, and this traveling field induces aneddy current on the non-magnetic conductor plate 54 constituting thesecondary side element. The thus generated eddy current constitutes athrust generation source in cooperation with the traveling field.Further, in the illustrated example of FIG. 15, the movable piece i isdisposed only to the upper portion of the stationary piece O, but themovable pieces i may be disposed to both the upper and lower portionsthereof.

[0103]FIG. 16 shows a linear pulse motor 57 as another example of thelinear motor 51 (52).

[0104] With reference to FIG. 16, the movable piece i is, for example,composed of a central permanent magnet 58 and two magnetic core members59 and 60 opposed to each other with the permanent magnet 58 beinginterposed therebetween. One 59 of the magnetic cores is formed withfirst and second magnetic poles 61 and 62 magnetized in N-pole by thepermanent magnet 58 and, on the contrary, the other one 60 of themagnetic cores is formed with third and fourth magnetic poles 63 and 64magnetized in S-pole by the permanent magnet 58.

[0105] On the other hand, the stationary piece O is formed withstationary teeth 65, each having, a

-shaped section, extending in a direction normal to the longitudinaldirection of the stationary piece O equally with the same pitch. Themagnetic poles 61 to 64 are formed with magnetic pole teeth 61 a to 64a, respectively, each having the same pitch as that of the stationarypiece O.

[0106] A first coil 66 and a second coil 67 are wound up around thefirst magnetic pole 61 and the second magnetic pole 62 of the N-poleside and connected in series to each other so as to generate magneticfluxes opposed to each other in directions at a time when current flows.The first coil 66 and the second coil 67 are electrically connected to apulse generation source, not shown.

[0107] On the other hand, a third coil 68 and a fourth coil 69 are alsowound up around the third magnetic pole 63 and the fourth magnetic pole64 of the S-pole side and connected to a pulse generation source.

[0108] In the described arrangement, the first and second magnetic poles61 and 62 are arranged so that the magnetic pole teeth 61 a and 62 athereof are shifted from each other by ½ pitch in their phases, and thethird and fourth magnetic poles 63 and 64 are also arranged so that themagnetic pole teeth 63 a and 64 a thereof are shifted from each other by½ pitch in their phases. Furthermore, the magnetic pole teeth 63 a and64 a of the third and fourth magnetic poles 63 and 64 of the S-pole sideare shifted, by ¼ pitch in phases, from the first and second magneticpole teeth 61 a and 62 a of the first and second magnetic poles 61 and62 of the N-pole side.

[0109] The linear pulse motor is driven by the following operationtheory with reference to FIGS. 17A to 17D.

[0110] Pulses are inputted to the first and second coils 66 and 67 fromterminals a, and pulses are also inputted to the third and fourth coils68 and 69 from terminals b. That is, the pulses are inputted to theterminal a in a direction to energize the first magnetic pole 61 in thestate shown in FIG. 17A, to the terminal b in a direction to energizethe fourth magnetic pole 64 in the state shown in FIG. 17B, to theterminal a in a direction to energize the second magnetic pole 62 in thestate shown in FIG. 17C, and to the terminal b in a direction toenergize the third magnetic pole 63 in the state shown in FIG. 17D,respectively.

[0111] When the pulse is inputted to the terminal a in a direction toenergize the first magnetic pole 61 in the state shown in FIG. 17A, thefirst magnetic pole 61 maintains its stable state under the applicationof the magnetic fluxes of the permanent magnet 58 and the first coil 66.Next, in the state shown in FIG. 17B, when the pulse is inputted to theterminal b in a direction to energize the fourth magnetic pole 64, thefourth magnetic pole 64 is moved to a direction so as to maintain itsstable state, that is, in the right direction facing the drawing paperby ¼ pitch. As mentioned above, the movable piece is operatedcontinuously as shown in FIGS. 17C and 17D by passing alternately thepulse current.

[0112]FIG. 18 represents a linear D.C. motor 70 as another example ofthe linear motor.

[0113] With reference to FIG. 18, a movable piece of this example iscomposed of exciting coils 71 and yokes, and a stationary piece O iscomposed of magnets 72 and yokes. A plurality of exciting coils 71constituting the movable piece i are arranged along the longitudinaldirection thereof, and a plurality of magnets 72 constituting thestationary piece O are arranged along the longitudinal direction so asto provide alternately N- and S-poles.

[0114] The position of the movable piece i is detected by a sensor, andthe direction of the current passing the exciting coil 71 at thedetected position is changed sequentially reversely. The exciting coil71 generates a thrust force in accordance with the Fleming's left-handrule through the relative reaction between the exciting coils 71 and themagnets 72.

[0115] In the case where such linear D.C. motor is utilized, two sets oflinear motors 51 and 52 are disposed in the back-to-back arrangement,and in an arrangement that a distance between the adjacent secondaryside magnets 72, 72 is short, there causes a fear that an alternatingmagnetic field is caused between the magnets 72 and 72, which may causea defective operation. Accordingly, in the case where two sets of thelinear motors 51 and 52 are used in the back-to-back arrangement, thelinear induction motor 53 and the linear pulse motor 57, which do notutilize the secondary side magnets 72, could be effectively utilized.However, in an arrangement in which a relatively large distance could bemaintained on the secondary side, no adverse effect is not causedbetween the magnets 72 and 72, so that the linear D.C. motor 70 may beutilized.

[0116] The drive system incorporated with the linear motors 51 and 52 ofthe structures mentioned above will operate in the following manner.

[0117] When the current is applied to the movable pieces i and i′ of thefirst and second linear motors 51 and 52, suction (attracting) forceacts between the movable pieces i and i′ and the stationary pieces O andO′ to thereby move the inner rail 8 with respect to the outer rail 7 bya predetermined distance in the longitudinal direction thereof. In thiscase, the movable piece i of the first linear motor 51 moves forwardwith respect to the stationary piece O. However, with the second linearmotor 52, a current is applied to the movable piece i′ in a backwardmovement direction with respect to the stationary piece O′ because ofthe movement of the stationary piece O′, and as a reaction motionthereto, the stationary piece O′ is moved forward. Hence, the inner rail8 is slid with respect to the outer rail 7, and therefore, the entirestructure of the drive system is expanded and contracted.

[0118] In the structure utilizing the linear motors 51 and 52 as drivingsource, it is not necessary to utilize a ball screw or like, and hence,the inner rail can be moved at high speed with less noise. Furthermore,there is no need for locating a space for a rotary motor or like, thusmaking the drive system thin and compact in its structure. Stillfurthermore, since the two sets of linear motors 51 and 52 are arrangedbetween the inner rail 8 and the outer rail 7, two times of the thrustforce is obtainable and the excitation of the linear motors 51 and 52 isaveraged, thus making smooth the movement of the inner rail 7.

[0119] Still furthermore, the movable piece i of the first linear motor51 is mounted to a portion near the outer rail side rolling membercirculation passage 14 and the movable piece i′ of the second linearmotor 52 is mounted to a portion near the inner rail side rolling membercirculation passage 16, the points on which the thrust force is appliedare always positioned at portions near the the outer rail side rollingmember circulation passage 14 and the inner rail side rolling membercirculation passage 16 irrespective of the stroke of the inner rail 8.The inner rail 8 is supported by the outer rail 7 at the positions ofthe inner rail side rolling member circulation passage 16 and the outerrail side rolling member circulation passage 14. Accordingly, even if amoment causing pitching or yawing acts on the inner rail 8, the thrustforce can be stably generated for the inner rail 8.

[0120]FIG. 19 represents a drive system according to a furtherembodiment of the present invention. The drive system of this embodimentis incorporated with two sets of rod-type linear motors as first andsecond linear motors 51 and 52. This drive system is also composed of,like the drive system mentioned hereinbefore, an outer rail 7, an innerrail 8 supported by the outer rail 7 to be slidable in the longitudinaldirection thereof and first and second linear motors 51 and 52 disposedbetween the outer rail 7 and the inner rail 8 both having box-shapedsections so that the inner rail 8 is fitted into the outer rail 8. Firstand second rod-type linear motors are composed of rods O and O′ asstationary pieces and cylindrical coils i and i′ as movable pieces.

[0121] The cylindrical coil i of the first rod-type linear motor 51 ismounted to the front end portion of the outer rail 7 and, to this frontend portion, is also mounted an outer rail side bearer 75 supporting therod O′ of the second rod-type linear motor to be slidable in an axialdirection thereof. On the other hand, the cylindrical coil i of thesecond rod-type linear motor 52 is mounted to the rear end portion ofthe inner rail 8 and, to this rear end portion, is also mounted an innerrail side bearer 76 supporting the rod O of the first rod-type linearmotor to be slidable in an axial direction thereof. The operation theorydue to this arrangement is substantially the same as that of the drivesystem of the embodiment mentioned hereinbefore, and by operating thefirst and second rod-type linear motors 51 and 52, the distance betweenthe outer rail side bearer 75 and the inner rail side bearer 76 areexpanded or contracted, thus the inner rail 8 being slid with respect tothe outer rail 7. As mentioned above, the rod-type linear motors arealso usable as linear motors for the drive system of the presentinvention.

[0122] Description will be come back to the rolling guide devicehereunder.

[0123]FIG. 20 is a partial sectional view of a drive system using arolling guide device of a further embodiment of the present invention.The rolling guide device of this embodiment comprises, like the rollingguide device shown in FIGS. 1 to 3, an outer rail 7 as track rail and aninner rail 8 as movable rail supported to be slidable in thelongitudinal direction of the outer rail 7, and hence, like referencenumerals are added to elements or members corresponding to those shownin FIGS. 1 to 3. The embodiment of FIG. 20 is provided with a ball screw9 for driving the inner rail 8.

[0124] In the rolling guide device of the aforementioned embodiment,although the outer rail 7 and the inner rail 8 are formed with singleball rolling groove to each side portion thereof, in the rolling guidedevice of this embodiment, the outer rail 7 and the inner rail 8 areformed with two ball rolling grooves 11, 11 (totally four grooves) toeach side portion thereof as shown in FIG. 20 in section. That is, inthe rolling guide device of this embodiment, upper and lower two ballrolling grooves 11, 11 are formed respectively to each of the insidesurfaces of the opposing ridges 7 b, 7 b of the outer rail 7, i.e. fourball rolling grooves 11, 11 for the outer rail 7. On the other hand,upper and lower two loaded ball rolling grooves 15, 15 are formedrespectively to each of the outside surfaces of the opposing ridges 8 b,8 b of the inner rail 8, i.e. four loaded ball rolling grooves 15, 15for the inner rail 8 so as to oppose to the ball rolling grooves 11, 11of the outer rail 7, respectively.

[0125] An outer rail side ball circulation passage 14 for circulatingthe balls rolling between the inner rail 8 and the outer rail 7 isprovided to one end side in the longitudinal direction of the outer rail7 as like as that of the rolling guide device mentioned hereinbefore.This outer rail side ball circulation passage 14 is composed of upperand lower two passages, and more concretely, is composed of portions ofthe ball rolling grooves 11, 11, ball return passages A, A as rollingmember return passages substantially parallel to the ball rollinggrooves 11, 11 and a pair of rolling direction changing passagescommunicated with the ball rolling grooves 11, 11 and the ball returnpassages A, A.

[0126] An inner rail side ball circulation passage 16 for circulatingthe balls rolling between the inner rail 8 and the outer rail 7 isprovided to one end side in the longitudinal direction of the outer rail7 on the side opposing to the outer rail side ball circulation passage14. This inner rail side ball circulation passage 16 is composed ofupper and lower two passages, and more concretely, is composed ofportions of the loaded ball rolling grooves 15, 15, ball return passagesA, A as rolling member return passages substantially parallel to theloaded ball rolling grooves 15, 15 and a pair of rolling directionchanging passages communicated with the ball rolling grooves 11, 11 andthe ball return passages A, A.

[0127] In the illustration of FIG. 20, although it seems that the outerrail side ball circulation passage 14 and the inner rail side ballcirculation passage 16 are positioned on the same sectional surface, inan actual arrangement, the outer rail side ball circulation passage 14and the inner rail side ball circulation passage 16 are shifted in theirpositions as shown in FIG. 1.

[0128] The rolling direction changing passages, each having asemi-circular shape, constituting portions of the outer rail side ballcirculation passage 14 and the inner rail side ball circulation passage16 are formed to deflectors 79 mounted, as independent members, to theinner rail body 8 d and the outer rail body 7 d. The deflector 79 isutilized commonly for the outer rail side ball circulation passage 14and the inner rail side ball circulation passage 16 and is provided withvertical two rolling direction changing passages. The deflector 79 iscomposed of three sections 79 a, 79 b and 79 c which are splittablevertically along the rolling direction changing passage for easyformation of the vertical two tolling direction changing passages. Thesethree splittable sections 79 a, 79 b and 79 c are divided vertically atplanes including central lines of the rolling direction changingpassages. These three sections 79 a, 79 b and 79 c are positioned andassembled with each other through fitting of dowels and holes formed tothe respective sections. Furthermore, the deflector 79 is formed with astepped abutment portion 29 to position the deflector 79 at the timewhen it is mounted to the inner rail side ball circulation passage 16and the outer rail side ball circulation passage 14. Holes 33 are formedto the outer rail body 7 d and the inner rail body 8 d from the sidesthereof, and stepped portions 33 a are formed to inside surfaces ofthese holes 33. Accordingly, the deflector 79 is positioned with respectto the outer rail body 7 d and the inner rail body 8 d through theabutment of the stepped abutment portion 29 against the stepped portions33 a formed to the holes 33, i.e. outer rail body 7 d and the inner railbody 8 d.

[0129] The ball screw 9 is screw-engaged with the inner rail 8. Thisball screw 9 is composed of a screw shaft 10 having an outer peripheryon which a spiral ball rolling groove is formed, a nut (member) 22having an inner periphery to which a ball circulation passage includinga spiral loaded ball rolling groove corresponding to the ball rollinggroove formed to the screw shaft 10 and assembled with the screw shaft10 to be relatively movable thereto, and a number of balls arranged inthe ball circulation passage and circulating in accordance with therelative movement of the nut member 22 with respect to the screw shaft10.

[0130]FIG. 21 illustrates a contacting state of the ball rolling groove11, the loaded ball rolling groove 15 and the ball 12 or 13. The ballrolling groove 11 is formed as a single circular groove, so-called,circular arc groove, having a diameter slightly larger than a diameterof the ball so that the ball 12 (13) contacts the ball rolling groove 11at one point P1. On the other hand, the loaded ball rolling groove 15 isformed as a single circular groove, so-called, circular arc groove,having a diameter slightly larger than a diameter of the ball so thatthe ball 12 (13) contacts the loaded ball rolling groove 15 at one pointP2. Further, it is to be noted that a line L connecting the contactpoint P1 at which the ball 12 (13) and the ball rolling groove 11 arecontacted and the contact point P2 at which the ball 12 (13) and theloaded ball rolling groove 11 are contacted is defined herein as contactangle line L. In this meaning, the contact angle lines L1, L2, L3 and L4will be defined as shown in FIG. 20.

[0131] That is, with reference to FIG. 20, the mutually opposing twoball rolling grooves 11, 11 and the two loaded ball rolling grooves 15,15 are offset from each other so that the vertical two lines L1 and L2are inclined towards the horizontal line H passing the center of thescrew shaft 10 while reducing a distance therebetween.

[0132] Further, it is desired that a contact angle constituted by thecontact angle line L1 (L2) and the horizontal line H is approximately45o. The center of the screw shaft 10 is positioned on the line passingthe intermediate portion between the ball rolling grooves 11, 11 and onthe central line of a span of the loaded ball rolling grooves 15, 15.Furthermore, it is desired that the center of the screw shaft 10 (centerof the thrust force of the ball screw 9) is also positioned on a lineconnecting a point P3 of the left side contact angle lines L1 and L2 anda point P4 of the right side contact angle lines L1 and L2.

[0133] The moment load as shown in FIG. 8 will be easily loaded on therolling guide device of the present invention, and accordingly, thevertical load will be also easily born by the balls 12 and 13. However,the contact angle lines L1 and L2 between the balls 12, 13 and the ballrolling grooves 11, 11 and between the balls 12, 13 and the loaded ballrolling grooves 15, 15 are inclined with respect to the horizontal lineH, thus the vertical load acting on the inner rail 7 being effectivelyborn by the balls 12, 13. For this reason, the moment load as shown inFIG. 8 can be surely loaded. Particularly, by setting the inclinationangle to 45o, loads acting on the inner rail 7 from vertical and lateralfour directions can be effectively supported by the balls 12 or 13.Furthermore, the ball screw 9 may be smoothly operated by positioningthe center of the thrust force of the ball screw 9 on the lineconnecting the crossing point P3 of the left side contact angle lines L1and L2 and the crossing point P4 on the right side contact angle linesL1 and L2.

[0134]FIG. 22 illustrates a contacting state of a ball rolling groove 11b, a loaded ball rolling groove 15 b and the ball 12 (13) in a rollingguide device in which one ball rolling groove 11 b and one loaded ballrolling groove 15 b are formed laterally as like as the rolling guidedevice shown in FIGS. 1 and 3. The ball rolling groove 11 b and theloaded ball rolling groove 15 b are each formed as a Gothic arch groove.That is, by forming so-called Gothic arch groove in combination of theball rolling groove 11 b and the loaded ball rolling groove 15 b intotwo circular arcs, two contact angle lines L3 and L4 inclined from thehorizontal line H can be obtained to thereby effectively support thevertical load by the ball 12, 13.

[0135]FIG. 23 is an illustration of one embodiment, partially insection, of an essential portion of a drive system utilizing a rollingguide device using rollers 80 as rolling members. In this embodiment,the rollers 80 are utilized in place of the balls 12, 13 in the formerembodiments. In this embodiment of FIG. 23, the outer rail 7 is providedwith ridges 7 b, 7 b as mentioned before having opposing inside surfaces7 c, 7 c to which roller rolling grooves 81, each having a V-shapedsection with opening angle of 90°, are formed, respectively. On theother hand, the inner rail 8 has the opposing outside surfaces 8 c, 8 cto which loaded roller rolling grooves 82, each having a V-shapedsection with opening angle of 90°, are formed, respectively. Therefore,a roller rolling passage having substantially square cross section isdefined between the roller rolling groove 81 and the loaded rollerrolling groove 82. Within this roller rolling passage, a plurality ofrollers 80, 80, - - - are arranged in shape of cross (cross arrangement)so that axes of the adjacent two rollers 80 cross each other.

[0136] The structure of this embodiment other than the above mentionedstructure is substantially the same as that of the rolling guide devicementioned with reference to FIGS. 1 to 3, so that the descriptionthereof is omitted herein by adding the same reference numerals to thecorresponding portions or elements.

[0137] According to this embodiment, in which the rollers 80, 80, - - -are arranged in crossing shape, the rollers 80 can effectively supportthe vertical load.

[0138]FIG. 24 is an illustration of another embodiment, partially insection, of an essential portion of a drive system utilizing a rollingguide device using rollers 83, 84 as rolling members. In thisembodiment, the outer rail 7 is provided with ridges 7 b, 7 b havingopposing inside surfaces 7 c, 7 c each to which vertical two rollerrolling grooves 81, 81 each having a V-shaped section with opening angleof 90°, are formed, respectively. On the other hand, the inner rail 8has the opposing outside surfaces 8 c, 8 c each to which two loadedroller rolling grooves 82, 82 each having a V-shaped section withopening angle of 90°, are formed, respectively. Therefore, vertical tworoller rolling passages each having substantially square cross sectionare defined between the roller rolling grooves 81, 81 and the loadedroller rolling grooves 82, 82. Within these roller rolling passages, aplurality of rollers 83, 84 are arranged in parallel to each other(parallel arrangement) so that axes of the adjacent two rollers areparallel to each other.

[0139] The rollers 83 disposed in the upper side roller rolling passageare arranged so as to support the load acting in the direction shown bythe line L5 (different from the horizontal line H), and on the otherhand, the rollers 84 disposed in the lower side roller rolling passageare arranged so as to support the load acting in the direction shown bythe line L6 (different from the horizontal line H). Angles constitutedby the line L5 and the horizontal line H and by the line L6 and thehorizontal line H are defined approximately 45o, respectively. Thestructure of this embodiment of FIG. 24 other than the above-mentionedstructure is substantially the same as that of the rolling guide devicementioned with reference to FIG. 20 so that the description thereof isomitted herein by adding the same reference numerals to thecorresponding portions or elements.

[0140] According to this embodiment of FIG. 24, in which the rollers 83and 84 are arranged in the vertical two roller rolling passages and thedirections along which the rollers 83 and 84 can bear the loads areinclined with respect to the horizontal line H, so that the rollers 83and 84 can effectively support the vertical loads.

[0141] According to the various preferred embodiments or examples of thepresent invention mentioned above, the track rail side rolling membercirculation passage and the movable rail side rolling member circulationpassage, in which the rolling members rolling between the track rail andthe movable rail circulate, are formed to the track rail and the movablerail, respectively. Therefore, when the movable rail is slid withrespect to the track rail, the rolling members arranged between thetrack rail and the movable rail endlessly circulate in the track railside rolling member circulation passage and the movable rail siderolling member circulation passage while rolling therealong. Asmentioned, since the rolling members circulate in the endless manner,even if the rolling member be slid during the rolling motion, there isno causing of a case that a cage is shifted from the initial position asin the conventional structure, and hence, a large expansion(contraction) stroke can be realized. Furthermore, in an optionalexpanded (contracted) attitude, there remains a relatively largedistance between the track rail side rolling member circulation passageand the movable rail side rolling member circulation passage, so that arolling guide device, which can bear even the moment load, can berealized.

[0142] Furthermore, according to the present invention, since the linearmotor means is incorporated between the track rail and the movable rail,no specific ball screw or like mechanism is needed, so that the movablerail can be moved at high speed with reduced noise.

[0143] It is further to be noted that the present invention is notlimited to the described embodiments and many other changes andmodifications may be made without departing from the scopes of theappended claims.

What is claimed is:
 1. A rolling guide device comprising: a track railformed with a rolling member rolling surface extending along alongitudinal direction thereof; a movable rail formed with a loadedrolling member rolling surface extending along a longitudinal directionthereof so as to oppose to the rolling member rolling surface of thetrack rail; a track rail side rolling member circulation passage formedto the track rail so as to circulate the rolling members rolling betweenthe track rail and the movable rail; a movable rail side rolling membercirculation passage formed to the movable rail so as to circulate therolling members rolling between the track rail and the movable rail; anda number of rolling members disposed and arranged in the track rail siderolling member circulation passage and the movable rail side rollingmember circulation passage.
 2. A rolling guide device according to claim1, wherein said track rail side rolling member circulation passage isformed to one longitudinal end side of the track rail and said movablerail side rolling member circulation passage is formed to onelongitudinal end side, opposing to said one end side of the track rail,of the movable rail.
 3. A rolling guide device according to claim 1,wherein said track rail has an opened recess having a

-shaped section and has inside surfaces to which said rolling memberrolling surfaces are formed, said movable rail is fitted into the recessof the track rail, and said movable rail has outside surfaces to whichthe loaded rolling member rolling surfaces are formed so as to oppose tothe rolling member rolling surfaces formed to the track rail insidesurfaces.
 4. A rolling guide device according to claim 3, wherein saidtrack rail side rolling member circulation passage is provided with arolling member return passage substantially parallel to said rollingmember rolling surface and a rolling direction changing passagecommunicating the rolling member rolling surface and the rolling memberreturn passage, said movable rail side rolling member circulationpassage is provided with a rolling member return passage substantiallyparallel to said loaded rolling member rolling surface and a rollingdirection changing passage communicating the rolling member rollingsurface and the rolling member return passage, said rolling directionchanging passages of the track rail side rolling member circulationpassage and the movable rail side rolling member circulation passage areformed to a deflector which is formed independently from a track railbody and a movable rail body, and said deflector is fitted to holesformed to the track rail body and movable rail body from side portionsthereof.
 5. A rolling guide device according to claim 4, wherein saidreturn passages are drilled to the track rail body and the movable railbody from longitudinal end portions thereof.
 6. A rolling guide deviceaccording to claim 4, wherein said deflector is composed of a pluralityof sections splittable along the rolling direction changing passages. 7.A rolling guide device according to claim 4, wherein said deflector ismade of a synthetic resin.
 8. A drive system comprising: a track railformed with a rolling member rolling surface extending along alongitudinal direction thereof; a movable rail formed with a loadedrolling member rolling surface extending along a longitudinal directionthereof so as to oppose to the rolling member rolling surface of thetrack rail; a track rail side rolling member circulation passage formedto the track rail so as to circulate the rolling members rolling betweenthe track rail and the movable rail; a movable rail side rolling membercirculation passage formed to the movable rail so as to circulate therolling members rolling between the track rail and the movable rail; anumber of rolling members disposed and arranged in the track rail siderolling member circulation passage and the movable rail side rollingmember circulation passage; and a linear motor means having a primaryside mounted to either one of the track rail and the movable rail and asecondary side mounted to another one of the track rail and the movablerail.
 9. A drive system according to claim 8, wherein said track railside rolling member circulation passage is formed to one longitudinalend side of the track rail and said movable rail side rolling membercirculation passage is formed to one longitudinal end side, opposing tosaid one end side of the track rail, of the movable rail, and saidlinear motor means comprises first and second linear motors, said firstlinear motor having a primary side mounted to a portion near the trackrail side rolling member circulation passage of the track rail, saidsecond linear motor having a secondary side mounted to the track railalong the longitudinal direction thereof so as to be continuous to theprimary side of the first linear motor, and said second linear motorhaving a primary side mounted to a portion near the movable rail siderolling member circulation passage of the movable rail, said firstlinear motor having a secondary side mounted to the movable rail alongthe longitudinal direction thereof so as to be continuous to the primaryside of the second linear motor.
 10. A drive system according to claim9, wherein said first and second linear motors are linear inductionmotors having secondary sides being opposed to each other.
 11. A drivesystem according to claim 9, wherein said first and second linear motorsare linear pulse motors having secondary sides being opposed to eachother.
 12. A drive system according to claim 8, wherein said track railhas an opened recess having a

-shaped section and has inside surfaces to which said rolling memberrolling surfaces are formed, said movable rail is fitted into the recessof the track rail, and said movable rail has outside surfaces to whichthe loaded rolling member rolling surfaces are formed so as to oppose tothe rolling member rolling surfaces formed to the track rail insidesurfaces.